Neophyten in der urbanen Gehölzvegetation von Graz

Die vorliegende Arbeit beschreibt die neophytenreiche Gehölzvegetation der Stadt Graz. Zu diesem Zweck wurden 129 pflanzensoziologische Aufnahmen von Gehölzbeständen erstellt, an deren Aufbau zumindest eine neophytische Holzart beteiligt ist. Die Daten wurden nach floristischen Ähnlichkeiten in fünf Vegetationseinheiten gegliedert: Mesophile Buchenwälder, Eichen-Hainbuchenwälder, Thermophile Buchenwälder, Monodominante Neophytengesellschaften und urbane Gebüsche. Es zeigte sich einerseits eine geographische Differenzierung innerhalb des Stadtgebietes und andererseits eine unterschiedlich starke Beeinflussung der Bestände durch Neophyten. Die Parameter, welche die floristische Zusammensetzung der neophytenreichen Gehölzvegetation bestimmen, sind neben dem starken anthropogenen Einfluss an den jeweiligen Standorten auch klimatische Faktoren. Dabei spielen die Lage der Stadt am südöstlichen Alpen-rand und die typischen Eigenschaften der Stadtflora eine bedeutende Rolle.This paper investigates the neophytic woody vegetation in the city of Graz. For this purpose, such vegetation types were located and 129 phytosociological relevés were performed in the study area. The data were sorted by floristic similarity into five units: mesophilous beech forests, oak-hornbeam woodlands, thermophilous beech forests, monodominant neophytic community assembly and urban shrubs. The results show a geographical differentiation and a varying impact of neophytic plants on these vegetation types. Thereby the typical traits of the urban flora and the urban environment are playing a central role

Lichenized fungi of the chestnut grove in Livari (Rumija, Montenegro)

Sixty taxa (59 species and 1 variety) of lichenized fungi are reported from a chestnut grove in Livari. The majority of them (55 species and 1 variety) occurred on Castanea sativa. The recently described Xylographa soralifera is new to the Balkan Peninsula.The lichenicolous fungus Monodictys epilepraria growing on Lepraria rigidula is new to Montenegro. The lichen mycota is compared with similar localities in Italy and Switzerland.The species composition in Livari is most similar to the Montieri site in Tuscany

The Vjosa River corridor: a model of natural hydro-morphodynamics and a hotspot of highly threatened ecosystems of European significance

Context: Large near-natural rivers have become rare in Europe, a fact reflected in the high conservation status of many riverine ecosystems. While the Balkan still harbors several intact river corridors, most of these are under pressure from planned hydropower constructions. Unfortunately, there is little information available on the hydromorphodynamics and biota of Balkan rivers under threat. Objectives: We present a synthesis of research on the Vjosa in Southern Albania. Here, longitudinal continuity in water flow, undisturbed sediment transport and intact fluvial dynamics are still maintained, but threatened by two large dams planned in its downstream section. We intend to provide a first multidisciplinary inventory of this river system as an example of the knowledge base required for sound water management decisions in the Balkans. Methods: Based on field work of a multidisciplinary consortium of scientists from Albania and other countries conducted from 2017 onwards, we summarize the most important findings on geomorphology of the riverine landscape, habitat turnover rates, vegetation ecology and selected animal taxa. Results: We found evidence that significant areas (86%) of the river corridor are covered by habitats listed in Annex 1 of the European Union Habitats Directive. These are associated with a high number of threatened biota. Conclusions: Our findings underscore the value of the Vjosa as one of the few remaining reference sites for dynamic floodplains in Europe and as a natural laboratory for interdisciplinary research. We emphasize that such multidisciplinary studies are a prerequisite for informed evaluation of potential impacts caused by hydropower plants

Rainforest transformation reallocates energy from green to brown food webs.

Terrestrial animal biodiversity is increasingly being lost because of land-use change1,2. However, functional and energetic consequences aboveground and belowground and across trophic levels in megadiverse tropical ecosystems remain largely unknown. To fill this gap, we assessed changes in energy fluxes across 'green' aboveground (canopy arthropods and birds) and 'brown' belowground (soil arthropods and earthworms) animal food webs in tropical rainforests and plantations in Sumatra, Indonesia. Our results showed that most of the energy in rainforests is channelled to the belowground animal food web. Oil palm and rubber plantations had similar or, in the case of rubber agroforest, higher total animal energy fluxes compared to rainforest but the key energetic nodes were distinctly different: in rainforest more than 90% of the total animal energy flux was channelled by arthropods in soil and canopy, whereas in plantations more than 50% of the energy was allocated to annelids (earthworms). Land-use change led to a consistent decline in multitrophic energy flux aboveground, whereas belowground food webs responded with reduced energy flux to higher trophic levels, down to -90%, and with shifts from slow (fungal) to fast (bacterial) energy channels and from faeces production towards consumption of soil organic matter. This coincides with previously reported soil carbon stock depletion3. Here we show that well-documented animal biodiversity declines with tropical land-use change4-6 are associated with vast energetic and functional restructuring in food webs across aboveground and belowground ecosystem compartments

Reducing Fertilizer and Avoiding Herbicides in Oil Palm Plantations—Ecological and Economic Valuations

Oil palm plantations are intensively managed agricultural systems that increasingly dominate certain tropical regions. Oil palm monocultures have been criticized because of their reduced biodiversity compared to the forests they historically replaced, and because of their negative impact on soils, water, and climate. We experimentally test whether less intensive management schemes may enhance biodiversity and lessen detrimental effects on the environment while maintaining high yields. We compare reduced vs. conventional fertilization, as well as mechanical vs. chemical weed control (with herbicides) in a long-term, full-factorial, multidisciplinary experiment. We conducted the experiment in an oil palm company estate in Sumatra, Indonesia, and report the results of the first 2 years. We measured soil nutrients and functions, surveyed above- and below-ground organisms, tracked oil palm condition and productivity, and calculated plantation gross margins. Plants, aboveground arthropods, and belowground animals were positively affected by mechanical vs. chemical weed control, but we could not detect effects on birds and bats. There were no detectable negative effects of reduced fertilization or mechanical weeding on oil palm yields, fine roots, or leaf area index. Also, we could not detect detrimental effects of the reduced fertilization and mechanical weeding on soil nutrients and functions (mineral nitrogen, bulk density, and litter decomposition), but water infiltration and base saturation tended to be higher under mechanical weeding, while soil moisture, and microbial biomass varied with treatment. Economic performance, measured as gross margins, was higher under reduced fertilization. There might be a delayed response of oil palm to the different management schemes applied, so results of future years may confirm whether this is a sustainable management strategy. Nevertheless, the initial effects of the experiment are encouraging to consider less intensive management practices as economically and ecologically viable options for oil palm plantations

Global fine-resolution data on springtail abundance and community structure

Springtails (Collembola) inhabit soils from the Arctic to the Antarctic and comprise an estimated ~32% of all terrestrial arthropods on Earth. Here, we present a global, spatially-explicit database on springtail communities that includes 249,912 occurrences from 44,999 samples and 2,990 sites. These data are mainly raw sample-level records at the species level collected predominantly from private archives of the authors that were quality-controlled and taxonomically-standardised. Despite covering all continents, most of the sample-level data come from the European continent (82.5% of all samples) and represent four habitats: woodlands (57.4%), grasslands (14.0%), agrosystems (13.7%) and scrublands (9.0%). We included sampling by soil layers, and across seasons and years, representing temporal and spatial within-site variation in springtail communities. We also provided data use and sharing guidelines and R code to facilitate the use of the database by other researchers. This data paper describes a static version of the database at the publication date, but the database will be further expanded to include underrepresented regions and linked with trait data.</p

Die Verwendung von Vegetations-Indikatoren zur Erklärung der Ausbreitung gebietsfremder Baumarten in temperaten Wäldern

Central European temperate forests are – with the exception of floodplain forests – relatively little invaded by alien plants. However, despite substantial recent progress, there is still a lack of using vege-tation plot data for analyzing spatio-temporal patterns of alien tree species invasions. We calculated relevé-based metrics of tree species’ ecological preferences using 19,413 phytosociological forest relevés of the Austrian vegetation database. We focused on the five most widely distributed alien trees, i.e. two archaeophytes (Castanea sativa, Juglans regia) and three neophytes (Acer negundo, Ailanthus altissima, Robinia pseudoacacia). For each of these species we analyzed the mean cover in the tree layer and the occurrence in the herb and shrub layers in relevés colonized by adult trees as a measure for persistence. Further, we evaluated the intergenerational ecological plasticity (= the ability of young trees to grow under different site conditions than adults) for the tree species, and the mean relevé indicator values for light, nutrients, moisture and hemeroby. We then compared these alien and native tree species metrics. We found that A. altissima and R. pseudoacacia build up high mean cover values in invaded forests, but this was not the case for the other alien trees. Thus, both species strongly affected forest communities of invaded sites. Similarly, the two species were common in the lower vegetation layers indicating recruitment under the canopy of adult conspecifics; this was facilitated by their ability to produce root suckers. Highest values of inter-generational ecological plasticity occurred in native pioneer trees and species of softwood floodplain forests, while alien trees had moderately high (A. negundo, A. altissima, J. regia) to low values (C. sativa, R. pseudoacacia). With the exception of C. sativa, all alien species showed high mean Ellenberg indicator values for light and nutrients, and were more common in sites with high hemeroby and high mean Ellenberg indicator values for temperature. Distinct from the ecological preferences of alien trees, and thus rarely invaded, were montane beech forests, coniferous mountain forests and forests at extremely dry sites, as well as swamp and bog forests dominated by willows and ash. We conclude that relevé-based metrics of the behavior of alien tree species allow new insights into the spatio-temporal dynamics of invasion of woody species in forests. Future work should expand this approach, e.g., by considering the role of life history traits and actual site conditions.In Mitteleuropa gelten die zonalen Waldgesellschaften als relativ resistent gegen Invasionen durch fremdländische Baumarten. In der vorliegenden Arbeit werden das ökologische Verhalten der in Österreich am weitesten verbreiteten baumförmigen Neophyten (Robinia pseudacacia, Acer negundo, Ailanthus altissima) sowie der Archäophyten Castanea sativa und Juglans regia untersucht. Ziel der Arbeit war es, an Hand der Artenzusammensetzung der Vorkommen in der Kraut-, Strauch- und Baum-Schicht herauszufinden, in wie weit die betreffenden Arten bereits erfolgreich in vorhandene natürliche Waldgesellschaften eingedrungen sind. Aus der österreichischen Vegetationsdatenbank (WILLNER et al. 2012) wurden 19.413 Vegetationsaufnahmen mit den 34 häufig vorkommenden Baumarten (> 100 Vorkom-men in einer der drei Vegetationsschichten, siehe Tab. 1) selektiert, die eine Baumschicht aufwiesen. Für die Analyse wurde eine unterschiedliche Artzusammensetzung (co-occurence) in den verschiedenen Vegetationsschichten als Indikator für unterschiedliche ökologische Schwerpunkte der Artvorkommen in den einzelnen Schichten verwendet. Für die Berechnungen wurden die Dominanz (mittlere Deckungswerte für die einzelnen Arten in der Baumschicht), eine Detrended Correspondence Analysis (DCA), mittlere Zeigerwerte der Einzelaufnahmen nach Ellenberg für die Größen Licht, Nährstoff, Feuchte und Temperatur sowie mittlere Hemerobiestufen der Einzelaufnahmen unter Verwendung von KLOTZ & KÜHN (2002), deren Angaben in eine Ordinalskala überführt wurden, herangezogen. Für die Beurteilung der Art des Eindringens in vorhandene Waldbestände nutzten wir das Konzept von GRIME (2001) mit den Grundtypen C-, S- und R-Strategie. Als Maß, inwieweit eine Baumart ihren einmal eroberten Standort behauptet (wir nennen es hier "Persistenz"), haben wir den Anteil jener Aufnahmen berechnet, in denen die Art in der Kraut- oder Strauchschicht zusammen mit Exemplaren der eigenen Art in der Baumschicht vorkommt. Als Maß, inwieweit eine Art als Sämling oder Jungpflanze sich in neuen Lebensräumen etablieren kann (wie nennen es hier "ökologische Plastizität"), haben wir den Abstand zwischen den Zentroiden der Arten in einzelnen Schichten innerhalb des dreidimensionalen DCA-Raumes verwendet

On the phytosociological affinities of communities with Fritillaria meleagris on the border between central and southeastern Europe

Im südöstlichen Österreich, im angrenzenden Westungarn und Nordostslowenien wurden insgesamt 31 Bestände mit Fritillaria meleagris pflanzensoziologisch erfasst, ausgewertet und durch Bodendaten ergänzt. In folgenden Pflanzengesellschaften konnte die Schachblume nachgewiesen werden: Pruno-Fraxinetum, Pseudostellario-Carpinetum, Galio palustris-Caricetum ripariae, Lysimachio vulgaris-Filipenduletum caricetosum acutiformis, Iridetum sibiricae, Serratulo-Festucetum commutatae, Silaetum pratensis, Festuco pratensis-Alopecuretum pratensis. Die Auswertung zeigt, dass F. meleagris im Untersuchungsgebiet eine breite phytocoenologische Amplitude hat und nicht als Charakterart einer bestimmten Assoziation aufgefasst werden kann. Alle Standorte weisen Eingriffe in den Bodenwasser-haushalt in Form von Entwässerungsmaßnahmen auf, die sich aufgrund der sand- und schluffreichen, meist hydromorphen Böden z. T. erst allmählich auf die Artenzusammensetzung der Flächen auswir-ken. Besonders die Vorkommen im Arrhenatherion sollten dringend einem Monitoring unterzogen werden, um einen weiteren Rückgang der Art erkennen und verhindern zu können.Vegetation and soil data have been sampled from 31 plots with Fritillaria meleagris in southeastern Austria, adjacent western Hungary and northeastern Slovenia. Fritillaria meleagris occurs in the following associations: Pruno-Fraxinetum, Pseudostellario-Carpinetum, Galio palustris-Caricetum ripar-iae, Lysimachio vulgaris-Filipenduletum caricetosum acutiformis, Iridetum sibiricae, Serratulo-Festucetum commutatae, Silaetum pratensis and Festuco pratensis-Alopecuretum pratensis. Our data demonstrate the broad phytocoenological amplitude of F. meleagris and do not support its recognition as character species of a particular association. All sites have been affected by the construction of drainage ditches, which is just beginning to be reflected in the floristic composition of the vegetation. We strongly recommend starting a monitoring program especially for the Arrhenatherion stands. The resulting measures could prevent the ongoing decline of the species